The radio communication frequency spectrums are valuable natural resources. The frequency spectrum resources become increasingly scarce along with the rapid development of radio communications. At present, a fixed frequency spectrum allocation is applied to a radio communication network, and the related departments and organizations have identified from their monitoring and studies on the radio communication frequency spectrums that some frequency bands (e.g., a TV frequency band) are idle in the majority of periods of time or in the majority of regions, whereas some frequency bands are competed for by multiple systems and multiple users at the same time, that is, there are no sufficient frequency spectrum resources for some system carrying a large amount of traffic, whereas too many frequency spectrum resources are occupied by some system carrying a small amount of traffic.
In order to improve the utilization ratio of the frequency spectrum resources, the technology of Cognitive Radio (CR) has emerged in response to this. A general idea thereof lies in that a change to the current radio communication environment is detected, and an white space frequency band of an incumbent system is selected dynamically for communication, without any interference with the incumbent system, to avoid the frequency spectrum resources from being accessed unreasonably at present as a result of fixed allocation of the frequency spectrum, where the white space frequency band refers to a frequency band allocated to the incumbent system and being in an idle state. Based on the technology of cognitive radio, an access system which can access the idle-state frequency spectrum allocated to the incumbent system for communication will be referred to as a cognitive system.
There are generally two categories of application scenarios of cognitive radio, where the first category relates to an opportunistic access to the frequency spectrum of the incumbent system, for example, an International Mobile Telecommunication (IMT) system accesses an white space frequency band of a radio and TV system; and the second category relates to an opportunistic access of multiple cognitive systems to some frequency band which is not authorized individually to any system, but accessed fairly by the multiple systems.
In the first category of scenarios, the service performance of the incumbent system, or a system at a high priority is required to be guaranteed, and particularly the cognitive system determines accurately which frequency bands are available white space frequency bands (some cognitive system can be introduced to these frequency bands without any influence upon normal operation of the incumbent system, or the system at a high priority); and if the occupied frequency bands become not available any longer, that is, the incumbent system, or the system at a high priority becomes operative, then the cognitive system will give up these frequency bands to the incumbent system, or the system at a high priority.
In the second category of scenarios, there is such a more typical application scenario that multiple operators share some frequency bands under the management by a centralized frequency spectrum manager, that is, dynamic frequency spectrum allocation or sharing problem is involved. Dynamic frequency spectrum allocation or sharing is essentially a multi-objective optimization problem, and since respective participants (including a frequency spectrum administrative department, an authorized user, an operator, and a cognitive user) belong to different organizations, and have different objectives and benefits, their decisive behaviors may affect each other, and have a competitive and cooperative relationship with each other. In this case, it may be crucial to design an access or allocation rule of the frequency spectrum, to coordinate the behaviors of the respective participants, to enable the frequency spectrum to be shared efficiently, to satisfy their different benefit demands, and to optimize the access efficiency of the frequency spectrum.
In summary, there has been absent so far a particular solution of frequency spectrum allocation in an application scenario where a frequency spectrum is shared by multiple operators or cognitive systems.